The study found that mice who could not smell lost around 16 per cent of their body weight

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In this file photo, A judges smells a pie as judging takes place in the World Scotch Pie Championship on November 16, 2010. Researchers at the University of California, Berkeley, found that mice that retained their sense of smell ballooned to twice their normal weight by eating the same amount of fatty food as the mice with no sense of smell.

Joey Tribbiani once famously claimed on "Friends" that, “Half the taste [of food] is in the smell.” And according to a new study, the more delicious that meatball sandwich smells, the higher the likelihood that your body may pack on the pounds.

Researchers at the University of California, Berkeley, found that mice who could smell gained twice their normal weight compared to smell-deficient mice who ate the same amount of fatty foods.

In addition, mice with boosted scent receptors, “super-smellers,” gained even more weight than those with a normal sense of smell.

The results of the new study were published in the journal Cell Metabolism, and the findings point to an unexplored link between olfactory neurons and weight gain.

After UC Berkeley researchers temporarily eliminated the sense of smell in the mouse on the bottom, it remained a normal weight while eating a high-fat diet. The mouse on the top, which retained its sense of smell, ballooned in weight on the same high-fat diet.
Photo credit: UC Berkeley

The study also found that the genetically-altered rodents who could not smell lost around 16 per cent of their body weight. The study suggests that not being able to smell food could have a surprising effect on the metabolism, potentially helping those struggling with weight loss remain thin even when eating fatty foods.

"Sensory systems play a role in metabolism. Weight gain isn’t purely a measure of the calories taken in; it’s also related to how those calories are perceived," said senior author Andrew Dillin, the Thomas and Stacey Siebel Distinguished Chair in Stem Cell Research, professor of molecular and cell biology and Howard Hughes Medical Institute Investigator. "If we can validate this in humans, perhaps we can actually make a drug that doesn’t interfere with smell but still blocks that metabolic circuitry. That would be amazing."

While it seems like something out of the Twilight Zone, Dillin pointed out eliminating a person’s smell may act as a future alternative for gastric bypass surgery.

"This paper is one of the first studies that really shows if we manipulate olfactory inputs we can actually alter how the brain perceives energy balance, and how the brain regulates energy balance," said Céline Riera, a former UC Berkeley postdoctoral fellow now at Cedars-Sinai Medical Center in Los Angeles.